whiteflame

How do you check the brake booster on a 69 vette to see if it is working properly ??? Brake pedal is sticking down close to the floor board. Have too pull back up with your toe. Car has all new rotors, pads and calipers and lines. Also a new master cylinder. Thnx Dave

Durango_Boy

With the engine off, press the brake pedal. It's supposed to get hard or stiff. If it doesn't the booster may be bad. If it does get hard, then start the car, and see if it gets soft under your foot. If yes, then the booster is fine.

Also, get on your back and look up at the top of the brake pedal arm. Is there a spring in place at the top? This is the brake pedal return spring. It by itself won't return the pedal but it does help and if it's not there it may contribute to the problem.

Finally, did you bench bleed the master before it was installed, and what method of bleeding did you use for the brakes after all the new parts were installed?

whiteflame

Durango Boy , thnx for the advice. My son and i bleed the brakes. Back right (inside) then outside to back left to front right to front left. Will check the spring. Thnx dave

whiteflame

After bleeding the brakes the other day, the brakes didn';t seem to bad. Then my son drove the car home 15 miles and the psdal started to stick down by the floor. Forgot to mention that brakes were not to bad at end of M/C change and bleeding . Dave

Durango_Boy

Well, if the brakes started out good, then went bad, and you didn't lose any fluid then you are either pushing an air pocket around in one of the lines, or the master simply has a bad seal in it. Not uncommon...I have installed a new master that was bad right off of the shelf.